Rajib K. Shaw, Ravi Sinha
The Gujarat Earthquake has caused a wide range of damage in different types of buildings in the urban areas, as well as rural areas. Here are some on-site observations and probable causes
The earthquake of January 26th, 2001 at 8:46 a.m. (IST) occurred on the RepublicDay, devastated the entire state of Gujarat causing extensive loss of life and property. The effect was particularly severe in the Kuchchh District,where more than 400 villages were affected. The number of life lost may vary from 30,000 to 50,000 while the number of affected people will be several millions. Gujarat being one of the most industrialised state of the country, a long-term economic effect of this earthquake is expected. Over 200,000 buildings have suffered severe to complete damage. This was a tragic blow to the region that was suffering from a draught conditions and the aftermath of two cyclones in last three years. The devastation has affected the area socially, economically and physically, and the measures adopted for its recovery should address issues along these aspects.
Confusion and lack of coordination exist among different stakeholders, which is possibly quite natural after such type of disasters. There is still confusion about the magnitude of the earthquake and the location of the epicenter. While the Indian Meteorological Department (IMD) measured 6.9 as the magnitude, USGS claimed it to be 7.9. The epicenter was inferred to be located in the north of Bhuj by IMD, while the USGS simulation shows it in the north of Bachau, which are almost 50 km apart. Confusion is also there regarding the number of casualty. It varies from 50,000 to 100,000. However, we could identify many positive activities among these turmoils and these events will possibly lead us to the right direction for long-term mitigation measures.
A wide range of damages has been noted in different types of buildings. In the urban areas, the multi-story reinforced concrete masonry structures have experienced severe damages, while in the rural areas many non-engineered buildings have experienced total collapse. The so-called soft-story problem is attributed to the collapse of many buildings in the urban areas. (Fig. 1,2, 3, 4, 5, 6)
However, it is not only an engineering issue, rather a cultural and socio-economic problem, and different stakeholders have their responsibilities. Besides the damages of the private buildings, there are also damages to the public buildings. Many key government offices have experienced partial or total collapse. The major hospital in Bhuj and the college is also destroyed. Many school buildings are also damaged in both rural and urban areas. The rural housing, which are made up of stones, adobe and bricks had undergone severe damages and in some cases total collapse. There were also damages to the infrastructures, both to rural and urban areas. Bridges have experienced minor damages and dislocation (without any collapse or major disruption of the system), roads were damaged with cracks (again without major disruption), and the port facility in Kandala had experienced severe liquefaction problems. The railway was also damaged, but same have been recovered soon. Similarly, the electric sub-station was damaged severely and many of them have been restored.
With this extremly damaged scenario, attempts are currently being made at all levels to bring back the normal life. However, the damage is so severe and intense that it is difficult for a single stakeholder to act independently and achieve the goal. Before going to the future perspective, let us summarise the possible causes of damages. In Ahmedabad and other urban areas, following might be the causes:
- Long-distant effects: The response spectra recorded in Ahmedabad shows some indication. However, it is subjected to additional scientific investigation.
- Effects of soft soil: It is known that the new Ahmedabad is located in the in-filled land. The very preliminary micro tremor measurement from our team shows that there are no strong site effects, at least in the measurement site.
- Structural system of the buildings: Soft story is the major issue here. We have seen the same type of construction for last 25 years. The soft story is according to the need of the inhabitant of the buildings: it is often used as the place for religious functions, party;
- Human Intervention: The other issues are also related to the local culture in Gujarat. People with additional amount of money are keen to change the interior of the houses, without any engineering perspective. There is a report to build swimming pool on the top of the house, which definitely affects the stability. The water problems in the area forces the residents to store water on the top of the buildings. There has been major damages in the stair cases. Last, but more importantly the cost of housing is relatively cheap in Gujarat (30 USD per sq. mtr. compared to 120 USD in Mumbai and other major cities). This contributes significantly to the quality of construction.
- Improper construction practices: There is often a tendency to increase the carpet area with the cantilever. In most of the cases, the building codes are not practiced in reality (unofficial data shows that it might be as less as 5% of the total buildings). There is often no soil test for the proper foundation.
- Root cause in the government mechanism: Building laws have not been made mandatory for most of the buildings. In spite of the fact there was enough existing knowledge of the risk, and most part of
Kachchh is located in the Zone 5 (in the scale of 1 to 5, and 5 being the most hazard prone), there was no proper attention to the building stocks. 80% of the buildings did not have their ‘building-use permit’, but the provision of water, electricity and sewage system was there. Moreover, government was receiving the building and property tax from those buildings. It was difficult to understand the system. Many useful documents were not available due to collapse of the key government buildings. There was no major plan to cope with the disaster, which is quite similar to the other states of India (only Maharastra has its own disaster management plan).
In contrast, the rural area damages and damages in the old part of the cities were attributed to lack of available skilled masons, lack of proper knowledge and awareness of earthquake resistant non-engineered buildings with little additional cost, lack of concern about seismic safety, lack of proper training and information dissemination. These are the basic factors and need more investment of time and efforts, rather than money. It needs people’s understanding, participation and involvement.
The government had a very effective relief mechanism. There was no scarcity of materials or resources. However, lack of prior practices and planning, it was difficult at the first stage to coordinate the activities. In many cases there were enough supply of materials, whereas in some case people were waiting for the relief. But fortunately, no major problem of law and order situation was observed. A very efficient, effective and coordinating mechanism was observed, the non-governmental organisations. The strong leadership of the local NGOs and their timely interventions were appropriate to bring down the confusion. They hosted regular meeting, and the international NGOs and UN bodies also participated in the activities. They went beyond the relief, and now currently getting involved in the rehabilitation process by adopting one or several villages. They formulated a shelter policy, and submitted to the government. This was the most significant part of their coordination that they had an extremely good and workable relation with the governmental organisations.
The government is currently posed with the big question of relocation versus in-situ reconstruction. From people’s perspective, it is definitely better to make the in-situ reconstruction of their houses. However, the huge rubbles need to be cleared and simultaneously the government mechanism is also tied up with the problem of tent-city versus temporary shelter. This is a problem of resources, expertise and time. There is also an urgent need for the damage assessment of the buildings, since many of the residents are living outside their homes in spite of minor damage to their buildings. A decision of retrofit or reconstruction or relocation will possibly come next. Time is very limited, and since the area has an extreme climatic condition, it is required to take the actions urgently. There are many potential funding and resources. A very much centralised coordination is needed to utilise the resources in the right direction.
In summary, the problems observed in this tragic event are no different from other major recent earthquakes in the world. As usual, there are huge amount of existing knowledge among the professionals and academic bodies, but these are not properly utilised by the entrepreneurs, decision makers and policy makers. In every level of government bodies, the understanding of the risk of the area seemed to be insufficient. Therefore, the attempt to the recovery and reconstruction process should have strong emphasis on: 1) proper understanding and awareness of the risk among different stakeholders, 2) sufficient level of training and confidence building among the professionals and the masons, 3) preparing appropriate planning and mitigation strategies for useful implementation.
Governments of India and Gujarat have undertaken a massive relief operation in cooperation with the non-governmental organisations and international agencies. The rescue operation is currently on the verge of completion, and the debris clearance is on progress. Now, it is more important to make an insight on the shelter and reconstruction issues. Although the national and provincial governments are doing their best to cope up with the present condition, the scale of devastation would require cooperation from different organisations in the recovery process. Basic facilities like health and education sectors have suffered severe damages both in the urban and rural areas. There is an urgent need for the recovery of these services, as well as to ensure its quality for the future events.
A preliminary survey in the affected areas show that the severe damage was caused by:
- the devastating nature of the earthquake (extreme magnitude),
- improper construction practices, which is often attributed to the lack of awareness and proper knowledge,
- lack of training of masons, engineers, builders etc., and
- lack of awareness of the risk.
Therefore, an attempt should be made to rectify these practices and raise awareness and build capacity and confidence among the local communities.
The recovery process should therefore be based on:
- self-reliance and participation of the community
- strengthening the local knowledge and economy and
- promoting local ownership and leadership. In this process, local values, cultures, and socio-economic conditions should be of utter importance.